The invention relates to an internal combustion engine in a hand-held power tool such as a motor chain saw, a cut-off machine, a trimmer, a blower or a similar device, wherein the internal combustion engine comprises a piston, a combustion chamber with a spark plug, and a crankshaft driven in rotation by the piston and supported in a crankcase. An intake for combustion air and fuel and an exhaust for combustion gases are provided. A wheel member is mounted on the crankshaft and rotates with the crankshaft. An alternator is driven by the crankshaft and supplies an electric consumer.
In the case of such internal combustion engines, it is known to use the alternator as an energy source for operating the ignition as well as for operating electric consumers, for example, a carburetor heater, a handle heater for a motor chain saw or the like.
In the housings of portable hand-held power tools, there is only little space available for arranging such an alternator. In order to deliver sufficient power, the alternator must be of an appropriate size and configured to be powerful. In this connection, it must be taken into consideration that an alternator in portable hand-held power tools is subjected to significant mechanical loads, for example, caused by vibrations. Also, the thermal behavior of the alternator must be designed to avoid damage at the alternator itself and/or at the components surrounding it.